高比容量Li_(2)ZnTi_(3)O_(8)@C⁃N负极材料储锂性能研究  

Li⁃Storage of Li_(2)ZnTi_(3)O_(8)@C⁃N Anode Materials with High Specific Capacities

作　　者：沈紫烨 王利娟 Shen Ziye;Wang Lijuan(School of Petrochemical Engineering,Liaoning Petrochemical University,Fushun Liaoning 113001)

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001

出　　处：《石油化工高等学校学报》2022年第3期1-9,共9页Journal of Petrochemical Universities

基　　金：辽宁省“兴辽英才计划”项目(XLYC1907025);辽宁石油化工大学第五层次人才基金项目(2018XJJ⁃012)。

摘　　要：以盐酸多巴胺为N、C源,高温固相法合成N掺杂C包覆Li_(2)ZnTi_(3)O_(8)@C⁃N负极材料。在合成过程中发现,部分Ti^(4+)被还原为Ti^(3+),达到了包覆和掺杂共同改性的目的。该方法有利于提高离子扩散系数和降低电荷转移电阻。在电流密度为0.5、1.0、1.5、2.0、2.5、3.0 A/g时,Li_(2)ZnTi_(3)O_(8)@C⁃N⁃2的放电比容量分别超过240.0、220.0、210.0、200.0、190.0、180.0 mA⋅h/g。还研究了N掺杂C包覆Li_(2)ZnTi_(3)O_(8)复合材料的低温电化学性能。结果表明,0℃时该样品的放电比容量远高于未改性的Li_(2)ZnTi_(3)O_(8)负极材料;电流密度为0.2 A/g时的首次放电比容量为262.5 mA⋅h/g,循环300次后放电比容量为241.7 mA⋅h/g;在电流密度为1.0 A/g、循环300次后放电比容量依然有147.4 mA⋅h/g。Li_(2)ZnTi_(3)O_(8) anodes coated with N⁃doped carbon from dopamine hydrochloride were synthesized via a high⁃temperature solid⁃state method.Some Ti^(4+)ions were reduced to Ti^(3+)ions during synthesis,which enabled the co⁃modification of coating and doping.The modification method can enhance the ion diffusion coefficients and reduce the charge⁃transfer resistance.In the rate performance tests at 0.5,1.0,1.5,2.0,2.5,3.0 A/g,the specific capacities of N⁃doped carbon⁃coated Li_(2)ZnTi_(3)O_(8)(Li_(2)ZnTi_(3)O_(8)@C⁃N⁃2)are over 240.0,220.0,210.0,200.0,190.0,180.0 mA⋅h/g,respectively.In addition,the electrochemical performance of this material at a low temperature was also studied.The results show that the Li_(2)ZnTi_(3)O_(8)@C⁃N⁃2 sample has much higher discharge specific capacities than those of unmodified Li_(2)ZnTi_(3)O_(8) anode material at 0℃.The initial discharge specific capacity is 262.5 mA⋅h/g at 0.2 A/g,and the discharge specific capacity of 241.7 mA⋅h/g is still obtained after 300 cycles.Even at 1.0 A/g,the discharge specific capacity is kept at 147.4 mA⋅h/g after 300 cycles.

关 键 词：锂离子电池 钛酸锌锂 负极材料 碳包覆 自掺杂 

分 类 号：TQ152[化学工程—电化学工业] TM911[电气工程—电力电子与电力传动]